This is not surprising, but nevertheless worrying, information. I would recommend that people read Vash "The Psychology of Disability". In her book she explores this in some depth. I use this knowledge when I am called upon to speak to a group; it has been proven that a person sitting in a wheelchair carries less "weight" than if that person were standing, and this is even true when the audience is made up of predominantly wheelchair users too. I therefore use other techniques (rolling about the stage, raising and lowering volume and tone of my presentation or lecture, etc.)
Enham - News Articles: "NEW RESEARCH REVEALS PREJUDICE AMONGST DISABLED PEOPLE
Dr Mark Deal, Research and Development Manager at Enham and PhD student at City University, London, has conducted a study which surprisingly reveals prejudice amongst disabled people against other impairment groups and that there exists a hierarchy of impairment based on a range of factors. For example: both disabled and non-disabled people rank those with a mental illness or learning disability as the least desirable, with deafness followed by arthritis as the most desirable or accepted form of impairment."